Mobile concrete pump

ABSTRACT

A mobile concrete pump with a chassis, a concrete distributing boom rotatable about a vertical axis and supported on a boom support, as well as with front support legs and rear support legs. Each front support leg and rear support leg arranged on the same side of the chassis of the chassis have a common pivot axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage of PCT/DE99/00877 filed Mar. 19,1999 and based upon German National application 298 11 097.0 of Jun. 20,1998 under the International Convention.

FIELD OF THE INVENTION

The invention relates to a mobile concrete pump with a chassis, aconcrete distributing boom rotatable about a vertical axis, arranged ona boom support, as well as with front support legs and rear supportlegs.

BACKGROUND OF THE INVENTION

Mobile concrete pumps as described above are used on construction sitesfor distributing concrete from a central location over a wide area sothat, in a pouring process with continuous concrete supply by means ofconcrete mixers, large concrete slabs can be produced. Furthermoremobile concrete pumps offer the possibility of transporting concrete tohigh-lying work levels with little effort, a purpose for which inpractice mobile concrete pumps whose distributing boom surpasses aheight of 60 m have already been used. At such dimensions it is obviousthat the stability of the mobile concrete pump presents a problem. Inorder to insure under all operational conditions a stable platform forthe mobile concrete pump with the desired extension of the distributingboom, the front and rear support legs are arranged on the chassis andcustomarily at the corners of the chassis. However this means that theentire chassis is exposed to the full impact of the distributing boomforce and therefore has to be manufactured to be correspondingly stable.For this reason the leg locations were changed by moving the pivotbearings for the front and rear support legs away from the chassiscorners and to bring them closer, so that the pivot bearing for the rearsupport legs is located close to the rear axle of the chassis. It hasbeen found that with the increasing closeness of the pivot bearings toone another torsion problems arise. Furthermore the pivot bearings ofthe front and rear support legs are arranged relatively far to the rearof the chassis, which requires that the front support legs be extendablevery far towards the front so that they are designed to be telescopic.Finally the boom support also projects very far forward on the chassis.As a result of the telescopic support legs and the projecting boomsupport the flexibility of the mobile concrete pump increased, whereactually stability is necessary and desired.

It is desired to spread the front and rear support legs as far away aspossible from the chassis to provide a secure stand. However the frontand rear support legs in their rest position have to be lodged on thepump in order to move it. Therefore, in order to be able to lodge asufficient length of the front and rear support legs on the chassis, ithas already been proposed to let the front support legs extendrearwardly and the rear support legs forwardly for storage, therebymaking use of the length offered by the chassis. However this requiressufficient available space at the construction site so that the frontand rear support legs can be deployed from their rest position to theirwork position in a circular motion passing over an apex. Furthermore insome mobile concrete pumps the support legs are telescopic so that inthe rest position only little space is required, while a wide range isavailable in the work position. The telescopes can impair the stability,aggravating by the increasing number of telescope segment.

OBJECT OF THE INVENTION

It is the object of the invention to provide a mobile concrete pump ofthe aforementioned kind so that expensive reinforcement of the chassisfor avoiding torsion between the pivot bearings of the front and rearsupport legs can be eliminated, and so that the front and rear supportlegs in long construction style can be lodged on the chassis withoutlarge space requirements during the transfer from the rest position tothe work position.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved in a mobile concretepump of the aforementioned kind in that each front support leg and rearsupport leg arranged on the same side of the chassis have a commonswivel axis.

This offers the advantage that only the area directly between the boomsupport and the pivot axis need be of a particularly stableconstruction, since the forces from the concrete distributing boom arechanneled directly via the boom support and this intermediate area tothe support legs, so that the rest of the chassis is not under load. Thearrangement of the pivot bearings on a common pivot axis offers anadditional space advantage, because the support legs can be made longerin the longitudinal direction of the chassis, since it is no longernecessary to provide a specimens between the swing bearings.

Advantageously the front support legs and the rear support legs aresupported on the boom support. During operation while pumping, theconcrete distributing boom with boom support and the front and rearsupport legs can be considered as a self-sufficient unit, which solelyfor the desired mobility is arranged on the chassis, which in itselfdoes not have to be reinforced, so that cost advantages result for themanufacturer, and furthermore the low inherent weight allows for greaterload. With regard to sufficient space availability for a stable supportit is advantageous when a base plate is assigned to the boom support, onwhich the front support legs and rear support legs are lodged.

Within the framework of the invention it is further provided that thefront support leg and the rear support leg on the same side arepivotally supported on a bolt arranged coaxially to the pivot axis. Thebolt forming a common pivot bearing for the front and rear support legsis fastened in a simple manner by means of a mounting.

A somewhat more complicated mounting is required when the front supportleg and the rear support leg on the same side are pivotally supported onseparate bolts coaxial with the pivot axis. However this offers theadvantage that torsion and bending forces acting on the boltsimultaneously from the front support leg and the rear support leg areavoided.

Each front support leg can be formed by a tubular guide rotatable aboutthe pivot axis, wherein a slide tube present in the support base of thefront support leg and traversing the tubular guide is slidably supportedin its rest position. This embodiment offers the advantage that thefront support leg in its rest position can be positioned on the chassisso that it does not project into the wheel boxes, which have to be keptclear for the wheels. Compared to a construction based exclusively ontelescopic means, the support leg has the advantage that the segmentconnected to the swing bearing does not limit the base length which isformed because of the distance between the clear space reserved for thesupport leg on the chassis and the pivot bearing. The frequentlypracticed move to place the swing bearings further rearward, in order tocreate a sufficient base length, and in this way to accept a shorteningof the rear support legs, as well as an indispensable reinforcement ofthe chassis, is no longer necessary.

Of course it is possible, in order to increase the range of the frontsupport legs, to design the slide tube as a telescope, this way alsomaking use of the inherent advantages, whereby the first segment of thetelescope can use the entire length of the slide tube.

In order to support the front leg on the chassis in the most compactmanner it is advantageous for the chassis to have a recess, into whichthe rear end of the slide tube can project. The part of the slide tuberearwardly projecting beyond the pivot axis can enter this recess andcan be swung and guided past the construction elements located on thechassis, in order to slide the slide tube into the tubular guide.

In alternative embodiment the rear support leg has a recess into whichthe slide tube projects in its rest position, and thus way the rearsupport leg can be thicker and more rigid without increasing thecumulative dimension of the rear and front support legs.

Suitably in this embodiment the rear support leg has two mounting platesby means of which it is connected to the bolt and between which thefront support leg is coupled with the bolt. In the rear support leg canbe left free between the mounting plates so that the pivot angle of thetubular guide is not impaired.

The concrete distributing boom with the boom support is mounted directlyon the chassis close to the front axle, which increases the rigidity andimproves stability due to the lack of intermediate members.

BRIEF DESCRIPTION OF THE DRAWING

The invention is explained in greater detail with reference to theembodiments illustrated in the drawing.

In the drawing:

FIG. 1 is a side view of the mobile concrete pump according to theinvention, with front and rear support legs in the rest position,

FIG. 1a is a representation corresponding to FIG. 1 of an embodimentwith the slide tube of the front support leg projecting into the rearsupport leg,

FIG. 2 is a top view of a schematic representation without concretedistributing boom, simplified with respect to FIG. 1,

FIG. 3 is a representation corresponding to FIG. 2 with an alternateposition of the front and rear support legs,

FIG. 4 a representation corresponding to FIG. 2 with the placement ofthe front support legs in reduced space conditions,

FIG. 5 a representation corresponding to FIG. 2 of an embodiment withmaximally extended front and rear support legs requiring the largestpossible work surface,

FIG. 6 is a top view on a boom support with front and rear support legs,with a sequence of the possible positions assumed during transition fromthe rest position into the work position,

FIG. 7 is a schematic representation of two coaxially arranged boltsforming the pivot bearings for the front and rear support legs,

FIG. 8 is a representation corresponding to FIG. 7 of an embodiment witha common bolt for the pivot bearings of the front and rear support legs,and

FIG. 9 is a representation corresponding to FIG. 7 of an embodiment witha slide tube according to FIG. 1a projecting into the rear support leg.

SPECIFIC DESCRIPTION

The mobile concrete pump illustrated in FIG. 1 comprises a chassis 2which is formed by a conventional truck with an operator cabin 3, afront axle 4 and a double rear axle 5 and a frame 6 connecting thesecomponents. On the chassis 2 a concrete distributing boom 7 is shown inits rest position. In the illustrated embodiment the boom 7 has boommembers 8 interconnected by articulations 9 and which can be displacedwith respect to each other by means of a hydraulic mechanisms 10. Thestrongest lower member 8 is connected to a boom support 11, which inturn is directly supported on the chassis 2 close to the front axle, inthe frontal third of the distance between the front axle 4 and thedouble axle 5. The concrete distributing boom 7 is rotatable about avertical axis 12, so that by the articulations 9 of the concretedistributing boom 7 any desired position can be reached within theradius corresponding to the concrete distributing boom in its extendedconfiguration. At the rear end of the chassis 2 a feeding box 13 isarranged, through which concrete is fed to a solid-material pump 14,which pumps the concrete through a duct 15 to the boom support 11 andthrough the same to a hose arranged on the concrete distributing boom 7,so that the concrete introduced through the feeding box 13 exits thehose at the free end of the concrete distributing boom 7 and can beprocessed there.

On the chassis 2 two front support legs 16 and two rear support legs 17are arranged, which serve for stabilizing the concrete pump 1 during thepumping process, so that a swinging motion of the concrete distributingboom 7 can take place without endangering the personnel or the material.The front support leg 16 and the rear support leg 17 respectivelyarranged on the same side of the chassis 2 have a common vertical pivotaxis 18, about which the swing or pivot bearing assigned to the frontsupport leg 16 and the rear support leg 17 can be rotated. The frontsupport legs 16 and the rear support legs 17 are fastened to a baseplate 19 assigned to the boom support 11 via the swing bearing. In FIG.7 with respect to the swing bearings an embodiment is shown wherein thefront support leg 16 and the rear support leg 17 sit on separate bolts20, 21, arranged coaxially with respect to each other and with respectto the pivot axis 18, while FIG. 8 shows an embodiment wherein only onebolt 20 coaxial with the pivot axis 18 is used.

Again from FIG. 1 can be seen that the front support leg 16 is formed bya tubular guide 22 pivotable about the pivot axis 18. In this tubularguide 22 a slide tube 23 is slidably supported, which in the restposition of the front support leg 16 shown in FIG. 1 projects rearwardthrough the tubular guide 22, so that the support base 24 arranged onthe slide tube 23, is placed in the rest position in a clear spaceavailable on the chassis 2. Further on the chassis 2 a recess 25 isformed, as can be seen from FIG. 2, into which the rear end of the slidetube 23 can project, so that for the transition of the front support leg16 from its rest position shown in FIG. 1 to its work position shown inFIG. 2, the tubular guide 22 with the slide tube 23 can be swung from aposition parallel to the longitudinal axis 26 of the chassis 2. For thisrotating motion only little space is required at the construction sitewhere the mobile concrete pump 1 is used, since the displacement of theslide tube 23 within the tubular guide 22 takes place only when thedesired pivot angle is reached. Then in this position the displacementof the slide tube 23 takes place, in order to displace the frontalsupport point sufficiently far away from the boom support 11. From FIGS.2-5 it can be seen that, depending on the existing space availability, adifferent positioning of the front support legs 16 is possible. In orderto increase the reach of the front support legs 16, the slide tube 23can be a telescope.

FIG. 1a shows a further embodiment wherein the rear support leg 17 has arecess 26 into which the slide tube 23 projects in its rest position.The rear support leg 17 has thereby two mounting plates 27, by means ofwhich it is attached to the bolt 20, whereby the front support leg isguided between the mounting plates 27 towards the bolt 20. In order notto reduce the pivot angle of the tubular guide 22 in this configuration,the rear support leg 17 is kept clear between the two mounting plates 27to the extent that the end of the tubular guide 22 facing the rearsupport leg 17 can be freely swung about the bolt 20.

I claim:
 1. A mobile concrete pump comprising a chassis, a concretedistributing boom rotatable about a vertical axis on a boom support onsaid chassis and a front support leg and rear support leg on eachlongitudinal side of the chassis, the respective front support leg andrear support leg arranged on the same side of the chassis having acommon pivot axis, the rear support leg having a receiving space intowhich a slide tube can project in a rest position thereof, the rearsupport leg having two mounting plates, by means of which it is attachedto a bolt forming the respective pivot axis and between which therespective front support leg is coupled to the respective bolt.
 2. Amobile concrete pump comprising: an elongated chassis having a front endand a rear end and a pair of longitudinal sides extending between saidends; a boom support on said chassis; a concrete distributing boomrotatable about a vertical axis on said boom support; a respective frontsupport leg and a respective rear support leg on each of saidlongitudinal sides and swingable away from said chassis to support theconcrete pump for operation of said boom; and respective pivots mountedon said boom support and on each of said longitudinal sides defining acommon vertical pivot axis for the respective front support leg and rearsupport leg on each longitudinal side, a baseplate being provided forsaid boom support, said pivots being formed on said baseplate wherebythe front support legs and the rear support legs are carried by saidbaseplate.
 3. A mobile concrete pump comprising: an elongated chassishaving a front and and a rear end and a pair of longitudinal sidesextending between said ends; a boom support on said chassis; a concretedistributing boom rotatable about a vertical axis on said boom support;a respective front support leg and a respective rear support leg on eachof said longitudinal sides and swingable away from said chassis tosupport the concrete pump for operation of said boom; and respectivepivots on each of said longitudinal sides defining a common verticalpivot axis for the respective front support leg and rear support leg oneach longitudinal side, each of said pivots being formed by a boltcoaxial with the respective pivot axis and supporting both the frontsupport leg and the rear support leg on the respective longitudinal sideof the chassis.
 4. A mobile concrete pump comprising: an elongatedchassis having a front end and a rear end and a pair of longitudinalsides extending between said ends; a boom support on said chassis; aconcrete distributing boom rotatable about a vertical axis on said boomsupport; a respective front support leg and a respective rear supportleg on each of said longitudinal sides and swingable away from saidchassis to support the concrete pump for operation of said boom; andrespective pivots on each of said longitudinal sides defining a commonvertical pivot axis for the respective front support leg and rearsupport leg on each longitudinal side, wherein each front support legbeing formed with a tubular guide swingable about the respective pivotaxis and a telescopic slide tube projecting through the tubular positionof the respective front support leg, said chassis having a recess intowhich a rear end of the slide tube can project, each rear support leghaving a receiving space into which a respective slide tube of therespective front support leg on the respective longitudinal side of thechassis can project in a rest position thereof.
 5. A mobile concretepump comprising: an elongated chassis having a front end and a rear endand a pair of longitudinal sides extending between said ends; a boomsupport on said chassis; a concrete distributing boom rotatable about avertical axis on said boom support; a respective front support leg and arespective rear support leg on each of said longitudinal sides andswingable away from said chassis to support the concrete pump foroperation of said boom; and respective pivots on each of saidlongitudinal sides defining a common vertical pivot axis for therespective front support leg and rear support leg on each longitudinalside, wherein each front support leg being formed with a tubular guideswingable about the respective pivot axis and a telescopic slide tubeprojecting through the tubular position of the respective front supportleg, said chassis having a recess into which a rear end of the slidetube can project, each rear support leg having two mounting plates forattachment to a bolt forming the respective pivot axis and between whichthe respective front support leg is coupled to the respective bolt. 6.The mobile concrete pump defined in claim 5 wherein the rear support legis left clear between the mounting plates so as not to interfere with apivot angle of the tubular angle guide.
 7. The mobile concrete pumpdefined in claim 5 wherein said chassis has at least one front axle andat least one rear axle and said boom support is located in a region ofsaid front axle.